1. Field of the Invention
The present invention relates to a plasma display panel, and more particularly, to a plasma display panel having a structure that can be simply manufactured, generates a stable discharge, and has improved brightness and light emission efficiency.
2. Description of the Related Technology
Recently, plasma display panels (PDPs) have received considerable attention as the next generation flat display devices due to their large screen size, large viewing angle, high image quality, ultra thin and light weight design, and simple manufacturing process when compared to other flat display devices.
PDPs can be categorized into direct current type PDPs and alternate current type PDPs according to the discharge type, and into facing discharge type PDPs and surface discharge type PDPs. Mainly, three-electrode surface discharge type PDPs are fabricated.
FIG. 1 is a cutaway exploded perspective view of a conventional three-electrode surface discharge type PDP. The PDP includes an upper panel 10 and a lower panel 20 facing the upper panel 10. Referring to FIG. 1, i) a pair of discharge electrodes 50 disposed on a lower surface of an upper substrate 11, ii) an upper dielectric layer 14 burying the discharge electrodes 50, and iii) a protection layer 15 covering the upper dielectric layer 14 are sequentially formed. One electrode of the discharge electrodes 50 is a common electrode 30 and the other electrode is a scanning electrode 40.
A plurality of address electrodes 22 extended to cross the discharge electrodes 50 and a lower dielectric layer 23 covering the address electrodes 22 are formed on an upper surface of a lower substrate 21. A plurality of discharge cells 60 are defined by barrier ribs 24 formed on the lower dielectric layer 23. A fluorescent layer 25 is formed on the lower dielectric layer 23 which is surrounded by the barrier ribs 24 across both side walls of the barrier ribs 24.
Each of the common electrode 30 and the scanning electrode 40 includes transparent electrodes 30a and 40a and bus electrodes 30b and 40b. The transparent electrodes 30a and 40a are formed of a transparent and conductive material that does not interrupt the progress of light emitted from the fluorescent layer, and typically formed of an indium tin oxide (ITO) film. However, due to its material characteristics, a particular patterning technique, such as sputtering which requires expensive equipment and a complicated process, must be used to form the ITO film.
Also, in order to improve the electric conductivity of the transparent electrodes 30a and 40a, additional aligning with the bus electrodes 30b and 40b is required since the bus electrodes 30b and 40b formed of a conductive metal must be formed on an outer end of the transparent electrodes 30a and 40a. Furthermore, when the bus electrodes 30b and 40b are formed on the ITO film, the bus electrodes 30b and 40b may not be melted or may not tightly contact the ITO film according to the kind of electrode material. The aligning of the ITO film with the bus electrodes 30b and 40b is also difficult since the ITO film is transparent.
In addition to the manufacturing difficulties, the light transmittance of the transparent electrodes 30a and 40a is approximately 80%, i.e., light loss is approximately 20%. The low light emission efficiency of the PDP is a disadvantage.
To solve these problems, a PDP in which discharge electrodes include only bus electrodes has been developed. However, in the PDP, a discharge cannot readily diffuse into the entire discharge cells since the bus electrodes having a narrow width are formed in consideration of the light transmittance, thereby reducing brightness and light emission efficiency.